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Cupressaceae FAMILY Least Concern

Juniperus virginiana silicicola

Juniperus virginiana silicicola

Edibility
2/5
Medicinal
2/5

Safety & Hazards

The essential oil in this plant contains thujone[1]. Thujone is a GABA receptor antagonist which allows neurons to fire more easily. In larger doses this can cause muscle spasms and convulsions, and can also be toxic to brain, kidney, and liver cells. There has been a lot of negative press regarding thujone, particularly in the mid 19th century when thujone was reported to be more dangerous than alcohol - since shown to be exaggerated; and reports in the 1970’s that it might have a similar effect on the brain to THC (found in cannabis) – since found to be incorrect. Thujone is probably best known for its use in the alcoholic drink ‘Absinthe’. It is also found in the essential oils of many other plants that are used in herbal medicines and foods, including Arborvitae (Thuja species), some Junipers (Juniperus species), Wormwoods (especially Artemisia absinthium) and Sage (Salvia officinalis). There are some legal restrictions in various countries on the quantity of thujone that can be added to foods and drinks and these vary between countries. Side effects from consuming thujone can include sleeplessness and anxiety but, unless the pure essential oil is used, the quantity of thujone found in plants is well within safety levels. Pregnant women, however, may be advised to restrict their use of thujone-containing plants. Juniper should not be used internally in any quantities by pregnant women[2, 3].

Cultivation Details

HabitEvergreen Tree
GrowthSlow

Juniperus virginiana silicicola is not a very cold-hardy plant, able to tolerate short-lived temperatures down to around -8°c when dormant. The climate is subhumid to humid, with a mean annual precipitation in the range 1,000 - 1,600mm and very mild winters[4]. Requires a sunny position. Succeeds in most soils if they are well drained, preferring a neutral or slightly alkaline soil[5, 6] and succeeding on chalk[7]. Tolerant of saline soils, salt-laden winds, and urban pollution[8, 9]. Established plants are drought tolerant, succeeding in hot dry positions[7]. This species is only hardy in the milder areas of the country, requiring a warm sunny sheltered position[10]. A very ornamental tree, it is moderately fast-growing for a juniper and is long-lived in the wild[11, 9]. Seed production is cyclic, a year of high yields being followed by some years of low yields[11]. This southern variety of Juniperus virginiana appears to be restricted mainly to coastal foredunes but differs little in morphology or leaf terpenoids from upland Juniperus virginiana and appears to intergrade with that variety in Georgia[12]. The crushed foliage has an aroma like soap or paint[13]. Plants are resistant to honey fungus[14]. In America this tree is a host of a gall-like rust that at certain stages in its life-cycle also attacks the leaves of apple trees[15]. Plants are dioecious, male and female plants must be grown if seed is required.

Propagation

The seed requires a period of cold stratification. The seed has a hard seedcoat and can be very slow to germinate, requiring a cold period followed by a warm period and then another cold spell, each of 2 - 3 months duration[16, 10]. Soaking the seed for 3 - 6 seconds in boiling water may speed up the germination process[6]. The seed is best sown as soon as it is ripe in a cold frame. Some might germinate in the following spring, though most will take another year. Another possibility is to harvest the seed 'green' (when the embryo has fully formed but before the seedcoat has hardened). The seedlings can be potted up into individual pots when they are large enough to handle. Grow on in pots until large enough, then plant out in early summer. When stored dry, the seed can remain viable for several years[5]. Cuttings of mature wood, 5 - 10cm with a heel, September/early autumn in a cold frame. Plant out in the following autumn[5, 16]. Layering in September/early autumn. Takes 12 months[16]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Juniperus+virginiana+silicicola>

Pollinators

Wind

References

  1. [1]Poisonous Plants of North Carolina — http://www.ces.ncsu.edu/depts/hort/consumer/poison/poison.htm ↩︎An excellent concise but comprehensive guide to toxic plants that grow in N. Carolina. It lists even those plants that are of very low toxicity, including several well-known food plants such as carrots and potatoes.
  2. [2]A Colour Atlas of Poisonous Plants. — Frohne. D. and Pfänder. J. · Wolfe · 1984 · ISBN 0723408394 ↩︎Brilliant. Goes into technical details but in a very readable way. The best work on the subject that I've come across so far.
  3. [3]The Dictionary of Modern Herbalism. — Mills. S. Y. ↩︎An excellent small herbal.
  4. [4]IUCN Red List of Threatened Species — http://www.iucnredlist.org/ ↩︎A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
  5. [5]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
  6. [6]Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. — Bean. W. · Murray · 1981 · ISBN - ↩︎A classic with a wealth of information on the plants, but poor on pictures.
  7. [7]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
  8. [8]Fire Effects Information System — http://www.feis-crs.org/feis/ ↩︎An on-line information site with comprehensive information on over 1,100 species of plant. Mainly developed to supply information on the effects of fire on plants and animals, it also contains a wealth of other information on the plants
  9. [9]Southern Trees Fact Sheets — Gilman E.F. · University of Florida, IFAS Extension · http://edis.ifas.ufl.edu/department_envhort-trees ↩︎A series of fact sheets on trees that can be grown in Florida. They can be downloaded from the Internet
  10. [10]Conifers. — Rushforth. K. · Christopher Helm · 1987 · ISBN 0-7470-2801-X ↩︎Deals with conifers that can be grown outdoors in Britain. Good notes on cultivation and a few bits about plant uses.
  11. [11]The Complete Trees of N. America. Field Guide and Natural History. — Elias. T. · Van Nostrand Reinhold Co. · 1980 · ISBN 0442238622 ↩︎A very good concise guide. Gives habitats, good descriptions, maps showing distribution and a few of the uses. It also includes the many shrubs that occasionally reach tree proportions.
  12. [12]Flora of N. America — http://flora.huh.harvard.edu/fna/ ↩︎An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
  13. [13]Conifers in the British Isles. — Mitchell. A. F. · HMSO · 1975 · ISBN 0-11-710012-9 ↩︎A bit out of date (first published in 1972), but an excellent guide to how well the various species of conifers grow in Britain giving locations of trees.
  14. [14]The Garden. Volume 112. — RHS. · Royal Horticultural Society · 1987 · ISBN - ↩︎Snippets of information from the magazine of the RHS. In particular, there are articles on plants that are resistant to honey fungus, oriental vegetables, Cimicifuga spp, Passiflora species and Cucurbits.
  15. [15]Trees of Central Texas. — Vines. R. A. · University of Texas Press · 1987 · ISBN 0-292-78958-3 ↩︎A good concise guide, it gives details of habitats and some of the uses of trees growing in Texas.
  16. [16]Propagation of Trees, Shrubs and Conifers. — Sheat. W. G. · MacMillan and Co · 1948 · ISBN - ↩︎A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
  17. [17]Manual of the Trees of N. America. — Sargent. C. S. · Dover Publications Inc. New York. · 1965 · http://www.biodiversitylibrary.org/ · ISBN 0-486-20278-X ↩︎Two volumes, a comprehensive listing of N. American trees though a bit out of date now. Good details on habitats, some details on plant uses. Not really for the casual reader. It can be downloaded from the internet.
  18. [18]Native American Ethnobotany — Moerman. D. · Timber Press. Oregon. · 1998 · ISBN 0-88192-453-9 ↩︎Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
  19. [19]A Modern Herbal. — Grieve. · Penguin · 1984 · ISBN 0-14-046-440-9 ↩︎Not so modern (1930's?) but lots of information, mainly temperate plants.
  20. [20]Earth Medicine, Earth Food. — Weiner. M. A. · Ballantine Books · 1980 · ISBN 0-449-90589-6 ↩︎A nice book to read though it is difficult to look up individual plants since the book is divided into separate sections dealing with the different medicinal uses plus a section on edible plants. Common names are used instead of botanical.
  21. [21]A Field Guide to Medicinal Plants. Eastern and Central N. America. — Foster. S. & Duke. J. A. · Houghton Mifflin Co. · 1990 · ISBN 0395467225 ↩︎A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
  22. [22]Aromatherapy - A guide for home use. — Westwood. C. · Amberwood Publishing Ltd · 1993 · ISBN 0-9517723-0-9 ↩︎An excellent little pocket guide. Very concise.
  23. [23]Trees of North Texas — Vines. R.A. · University of Texas Press. · 1982 · ISBN 0292780206 ↩︎A readable guide to the area, it contains descriptions of the plants and their habitats with quite a bit of information on plant uses.
  24. [24]Identification Guide to the Trees of Canada — Lauriault. J. · Fitzhenry and Whiteside, Ontario. · 1989 · ISBN 0889025649 ↩︎Very good on identification for non-experts, the book also has a lot of information on plant uses.
  25. [25]CosIng — http://ec.europa.eu/growth/tools-databases/cosing/ ↩︎CosIng is the European Commission database for information on cosmetic substances and ingredients.
  26. [26]Dictionary of Economic Plants. — Uphof. J. C. Th. · Weinheim · 1959 · ISBN - ↩︎An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
  27. [27]Plants for Man. — Schery. R. W. ↩︎Fairly readable but not very comprehensive. Deals with plants from around the world.
  28. [28]A Dictionary of Plants Used by Man. — Usher. G. · Constable · 1974 · ISBN 0094579202 ↩︎Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
  29. [29]The Herb Book. — Lust. J. · Bantam books · 1983 · ISBN 0-553-23827-2 ↩︎Lots of information tightly crammed into a fairly small book.
  30. [30]A Weavers Garden — Buchanan. R. · McGraw-Hill Contemporary · 1987 · ISBN 0934026289 ↩︎Covers all aspects of growing your own clothes, from fibre plants to dyes.
  31. [31]Plants for Ground Cover — Thomas. G. S. · J. M. Dent & Sons · 1990 · ISBN 0-460-12609-1 ↩︎An excellent detailled book on the subject, very comprehensive.